<!DOCTYPE html>
<title>Tests that scroll adjustment still applies when using another anchor in default anchor's scroll container</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#needs-scroll-adjustment">
<link rel="author" href="mailto:xiaochengh@chromium.org">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="support/test-common.js"></script>

<style>
body {
  margin: 0;
}

#scroller {
  width: 400px;
  height: 400px;
  overflow: scroll;
  position: relative;
}

#spacer {
  width: 1000px;
  height: 1000px;
}

.anchor {
  width: 50px;
  height: 50px;
  position: absolute;
  background: orange;
}

#anchor1 {
  anchor-name: --a1;
  left: 300px;
  top: 100px;
}

#anchor2 {
  anchor-name: --a2;
  left: 200px;
  top: 200px;
}

#anchor3 {
  anchor-name: --a3;
  left: 100px;
  top: 300px;
}

/* Uses different anchors in insets instead of the default anchor.
 * Still scroll-adjusted because they are in the same scroll container. */
#target {
  position: fixed;
  width: 50px;
  height: 50px;
  left: anchor(--a3 left);
  top: anchor(--a1 top);
  position-anchor: --a2;
  background: lime;
}
</style>

<div id="scroller">
  <div id="spacer"></div>
  <div class="anchor" id="anchor1"></div>
  <div class="anchor" id="anchor2"></div>
  <div class="anchor" id="anchor3"></div>
</div>
<div id="target"></div>

<script>
promise_test(async () => {
  await waitUntilNextAnimationFrame();
  assert_equals(target.getBoundingClientRect().left, 100);
  assert_equals(target.getBoundingClientRect().top, 100);

  scroller.scrollLeft = 50;
  await waitUntilNextAnimationFrame();
  assert_equals(target.getBoundingClientRect().left, 50);

  scroller.scrollTop = 50;
  await waitUntilNextAnimationFrame();
  assert_equals(target.getBoundingClientRect().top, 50);
}, '#target3 is scroll-adjusted in both axises');
</script>
